Born in Glasgow in 1880, Ms Macarthur was elected president of the Scottish National District Council of the Shop Assistants' Union in 1902, and a year later she was the first woman to be elected to its national executive.

'Truly remarkable woman'

In 1918, women workers on London buses and trams were the first to strike for equal pay, a moment she described as "a landmark for the women's movement and for trade unionism".

She also fought to end "sweated" labour, which saw women working from dawn until 11pm for less than a living wage, such as chainmakers who worked in garden sheds hammering out chain links for as little as five shillings for a 50-hour week.

During her investigation of sweated industries, she contracted diptheria.

She died in 1921 at her home in Golders Green.

Image copyrightTUCImage caption
Only one in eight of the more than 900 blue plaques in London are in recognition of women

Anna Eavis, curatorial director at English Heritage, described Ms Macarthur as a "truly remarkable woman".

"She was tireless in her battle for equal pay and better working conditions and was responsible at least in part for the introduction of a minimum wage and the regulation of 'sweated' working," she said.

Ms Eavis added that it was fitting to remember her achievements with a blue plaque during Women's History Month and on the eve of International Women's Day on Wednesday.

Image copyrightGoogleImage caption
She lived and died at 42 Woodstock Road

Frances O'Grady, general secretary of the Trades Union Congress, said: "Thanks to her and others like her there were more than a million women in unions by 1918."

The blue plaques scheme, taken on by English Heritage in 1986, has been running since 1866 to commemorate the notable people who lived and worked in buildings in London, with the first plaque, to the poet Lord Byron, put up in 1867.

Figures show that only one in eight of the more than 900 plaques are in recognition of women.